Expanding reamer



Oct' 2 1945` AH. E. MccALLloN 2,385,999 v EXPANDING BEAMER l tively.

Patented Oct. 2, 1945 YUNITED STATES f PATENT OFFICE vEXPANDINc. REAMER; Hugh E. Medallion, Roseville, Mich. Application November 1s, leili-,sefisi No.5s4p4 Y (o1. rif- 7st 7 Claims.

The' present invention relates to expanding reamers and has among its objects an expanding reamer capable of more rapid and accurate expansion and contraction than is possible with the conventional expanding reamer.

Another object is a reamer in which the blades are at all times and in any position provided with complete and rigid lateral support.

Other objects and advantages will readily occur tothose skilled in the art.upon reference to the following description and the accompanying drawing in which .Fig 1 is a longitudinal central section of a 4reamer embodying the present invention. r

Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is a view in elevation of one of the elements. f

Figs. 4 and 5 are end views of the outer and inner wedges respectively.

Figs. 6 and 7 are part sections on the line 6-16 of 4 and the line 'I-l of Fig. 5 respec- In the drawing, the reamer is shown as assembled around a central shaft `or rod I `p-rovided with oppositely threaded end portions upon which are threaded the two portions of the tubuf lar member II shown in elevation in Fig.` 3., n

This element I I is provided with a main smaller portion having enlargements I IA atits ends separatedfrom thesmaller portion by smooth angular shoulders IIB while at the extreme ends there may be provided further enlarged portions IIC, knurled or polygonal for convenience in handling. i

As shown, the element II will'be madein two portions having their adjacent ends intertting to prevent relative rotation.

As stated above, element II is threaded on the rod IIl by means of suitable internal threads. It is also threaded externally as shown with the two portions of its smaller diameter oppositely threaded and the enlarged ends IIA also oppositely threaded and each of the latter is opposite# ly threaded with respect to its adjacent portion of the smaller diameter. In other words, the portion A will have a right hand thread, the por"- tion B, a left hand thread, the portion C a right hand thread, and the portion D, a left hand thread. Y i

Threaded upon the enlarged ends of the element II are two rings I2 whose outer or end faces Yare flat and normal to thereamer axis and whose inner faces I2A constitute re-entrant cones, and threaded upon `the smaller portion if of element II are two rings I3 of which the axially outward faces are provided with conical faces adapted to interi-lt with the faces I2A of rings I2 and with the inclined shoulders IIB of element II. The axially inner faces of rings I3 are conical.`."The`. angles of the several cones are preferably 1 Located between these end rings and held thereby are a pluralityof wedge element`s, those designated bynumeral I5 being referred `toas outer wedges and those designated I6, as .innerf wedges. l e

In the preferred form as` shown, the outer wedges I5 consist of bars` having a `cross sectionalshape approximately that of `a sector ofa circle representing the reamer in its smallestad-` justment,` Kbut, whilelthe curved outer surfaces of these wedges are ares'oi such a circle, the side or flat faces are not radial but converge to include an angle greater. thanthe arc of the outer surface. yThe apex thus produced, lies just outsidethe perimeterofelemcntlI..

The inner wedgesv I E, as shown in Figure 5, have their inclined ilat. faces including amuch smaller angle than do the at faces of the outer wedges @and since theyliebetween the outer wedges, the base of the triangular cross sectional area .is near the element4 IFI.` VThis base ISA is, as shown, curved to conform to the curvature of elementr I I. v 1 n The ends of `both outer and inner wedges are curved to abutland coact with the rings at, the ends of the reamer.

Referring to Figures 4 to V7, it will be noted that wedge I5 is provided with two conic faces offset fromeach other. That is, on wedge I5, the lower or4 inner coneface ISA is set back a short distance from the upper or outer cone face I5B. It willbe noted that both wedges are pro-` vided with ribs I'I adapted to coact with suitable channels in the` cones of the end rings I2 and I 3. to prevent relative rotation of rings and Wedges` i l Other means for preventing relative rotation` may of course be used if desired.

As indicated best in Figures 2 and 5, the wedges I6 mayjbe provided at their outer edges with cut-V ting edges, as at 2B, either integral or inserted.

In the position of the parts as in Figure 1, it

' will 'be noted that the inner wedges I6 are drawn intonprovide the smallest diameterof the as.

semblyand if it is desired. so to do, the blades of wedges I B maybe within the perimeter and thus fully protected by the adjacent wedges I5. When it is desired to 'expand the reamer, the lock nuts 2| are loosened and backed offa short distance, the element II held to preventrotation and the rings and wedges rotated in theproper direction as a unit. This procedure causes the rings I3 to move toward each otherand the rings l2 to move away from each other.. `Such movement of rings I3 causes a radial movement of wedges I6 and this radial movement expands the wedges I5.

It should be noted that when the parts are in outward movement of the cutters.

the smallest diameter adjustment, the wedges I5 contact only the ring I2, not touching ring I3, and the wedges I6 contact only the ring I3 and do not touch ring I2.

In the largest diameter adjustment, wedges I5 and I6 both touch both rings, thus limiting the The range of adjustment is determinedfby the amount of displacement of the cone surfaces the one from the other on the ends of the wedges I5, in other words by the length of the line in Figure 6. Y

threaded that when the latter are rotated on said central member the cone members at either end move in opposite directions, longitudinal blade members having diagonal surfaces contacting the first pair of cone members, and longitudinal ller members between said blade members and having diagonal surfaces contacting the internal cones of the second pair of cone members and also having diagonal surfaces parallel with but displaced In the foregoing description, use has been made of the term cone to describe the action surfaces of the rings I2 and I3, but it is not necessary that these be truly conic, as they may be pyramidal as there is no relative rotary movement between them and the ends of the wedges I5 and I6. And, while the mechanism has been described and shown as a four bladed expansion reamer, a different number of blades, such as three, six, eight or other number lmay be used, and the mechanism may also be adapted for use as an expanding mandrel or for use as a clutch member and such uses are in contemplation.

In selecting the number and form of blades or. inner wedges to be used, no particular apex angle for the wedges is necessarily chosen since they may vary widely. It will always be the case, however, that the sum of the apex angles of the outer wedges less the sumof the apex angles of the inner wedges will equal 360. y

Further, by using threads of la different pitch on the portions A and D of element I I from those on portions Band C, the longitudinal .movement of rings I2 and I3 may be made to accord with the outward movement of the two sets of wedges so that the latter will always contact their respective rings. y

Now having described the invention and the preferred embodiments thereof, it is to be understood that said invention is to be limited, not to the specific details herein set forth, but only by the scope of the claims which follow:

I claim:

l. An expanding reamer having a central member threaded on its main portion with the threads toward one end opposite to those toward the other end, and having end portions also threaded with the threads of each said end portion opposite to the threads on the adjacent main portion, blade expanding rings` threaded on the main portions, blades seated thereon, and blade supporting wedge members between said blades, said wedge members being adjustably held by the rings threaded on the end portions.

2. In an expanding reamer, wedge shaped blade carrying members, having small apex angles and having their bases near the reamer axis, wedge shaped ller members between the blade carrying members, said ller members having their apices adjacent the reamer axis, means for moving said blade carrying members radially, and means for retaining said filler members while allowing them to be moved outwardly by said blade carrying members.

3. In an expanding reamer, a central threaded member, a pair of axially movable oppositely placed cone members carried thereby, a second pair of axially movable oppositely placed cone members on said central member located beyond the first pairA and having internal cones, said central member and cone members being so from the cones of the rst pair of cone members.

4. In an expanding reamer, a central threaded member, a pair of axially movable oppositely placed cone members carried thereby, a second pair of axially movable oppositely placed cone members on said central member located beyond the first pair and having internal cones, said centralv member. and cone members being so threaded that when the latter are rotated on said central member the cone members at either end move in opposite directions, longitudinal blade members having diagonal surfaces contacting the first pair of cone members, and longitudinal filler members between said blade members and having diagonal surfaces contacting the internal lcones at the second pair of cone members and also having diagonal surfaces parallel with but displaced from vthe cones of the rst pair of cone members, said cones and said contacting surfaces being provided with means to prevent relative movement when said cone members are rotated about said central member.

5. In an expanding reamer, a central threaded member, a pair of axially movable oppositely placed cone members carried thereby,.a second pair of axially movable oppositely placed cone members on said central member located beyond the first pair and having internal cones, said central member and cone members being so threaded that when the latter are rotated on saidcentral member the cone members at either end move in opposite directions, longitudinal blade membershaving diagonal' surfaces contacting the first pair of cone members, and longitudinal-filler members between said blade members and having diagonal surfaces contacting the internal cones of the second pair of cone members and also having diagonal surfaces parallel with but displaced from the cones of the first pair of cone members, said cones and said contacting surfaces being ribbed whereby to prevent relative movement when said cone members are rotated about said central member.

6. In an expanding reamer, Wedge-shaped radially arranged blade carrying members having bases near the reamer axis, Wedge shaped ller members between the blade carrying members, said ller members having their apices adjacent the reamer axis, means for moving radially the blade carrying members, and means for restraining the ller members While allowing them toy be moved outward by said blade carrying members.

7. In an expanding reamer, inner and outer wedge shaped members alternately and radially arranged about the axis -of said reamer, means for simultaneously moving radially said lwedge shaped members, and means for retaining said members while being moved, the sum of the apex angles of the outer wedge shaped members minus the sum of the apex angles of the inner wedge shaped members equally 360.

HUGH E. MCCALLION. 

